Process for the regeneration or revivification of purifying, filtering, and decolorizing agents



' 4o iviation nor' Patented Apr. 16, 1929.

UNITED STATES mm IooLAns anonr sauna, or ms'rnanm, NETHERLANDS; nonoaaAmmn PEDRO MARIE TERVOOREN, REPRESENTATIVE 01 Th E ESTATE OF SAID JOHANNIGOLAAS ADOLF SAUER, DECEASED, ASSIGNOR TO NAAMLOOZE VENNOOTSCHAP IALGEMEENE NORIT MAATSCHAIPPIJ, OF AMSTERDAM,

TION OF THE NETHERLANDS.

NETHERLANDS, A CORPORA- PBOOESS FOR THE REGENERATION OR REVIVIFIGATION FPULBJIYING, FILTERING, AND DEGOLORIZING AGENTS..

No Drawing. Application filed tlay 24, 1923, Serial No. 641,241, andin'Germany May 26, 192 3.

If any purifying, filtering or decolorizing agents e. g. so-calleddecolorizing carbon, wood charcoal,boneblack, blood charcoal, kieselguhror other infusorial earths, pumice 5 stone, silica, precipitated saltsor other compounds, insoluble in the liquid to be treated, as e. g.precipitated carbonate of lime, etc. are caused to act upon organicliquids or solutions 'of organic matters, as e. g. sugar solutions,

glucose, glycerine, fats, oils,-alcohol containing liquids, alkaloids,etc., the decolorizing or adsorbing agent will not only take up theinorganic and organic impurities, but it will besides be charged withpart of the materials to be purified or refined.

In the burning operation, as applied for revivifying said agents, theorganic matter taken up. or adsorbed, is carbonized in the own way.

The fine particles of carbon formed in the burning process afiect thedecolorizing, filtering and adsorbing capacity, while moreover they-addtothe bulk and weight of the agent.

Attempts have already been made to obviate these drawbacks by trying toremove the organic and inorganic matter prior to the burning operationby means of chemical agents, e. g. acids or alkaline substances,extraction means, or by fermentation.

In practice it was hitherto not possible in most cases to revivify theagents by the use of a chemical purification preceding the burningwithout impairing the adsorptive capacity.

It was experienced that the fact, that the revivification was notsatisfactory in every respect, was due to the formation of finesecondary carbon from said'unremoved organic matterby the burningprocess and thatneither by using'a mechanical extraction or li-xy usinga preliminary chemical or biologicaftreatment, the organic and inerganicmatter taken up could'be' removedncom pletely or at a sufiicient degreefrom the decolorizing agent. I

An object of the present invention is to provide for the removal of saidfine (secondary) carbon from the burned decolorizing, filtering oradsorbing agent; According to the invention the regenerated materialregains its initial efliciency and physical properties.

as much as possible of I have found as a result of my researcheswhat wasunknown until now in the art of regenerat1on-that organic matter taken uby the agent, not removed therefrom and carbonized in the burningprocess to form secondary carbon, can be removed, by treating said agentwlth suitable chemical agents, viz: with such agents, which are capableof decomposing or dissolving carbonaceous compounds and that by thistreatment the full adsorptive capacity could be restored.

' Such chemical agents are e. g. concentrated alkaline lyes,.sulfuricacid, nitric acid, hydrofluoric acid, hypochlorites, permanganate ofcalcium, etc., used separately or in combination.

In order to illustrate in which manner my invention may be carried out,the following example is stated:

Use is made of active, so-called decolorizing 7 carbon for thedecolorizing of sugar solutions. After use the carbon is washed out withhot water for the purpose of removing therefrom the bulk of sugar, andthe carbon is then burned. a

The burning operation being accomplished, Y the carbon is boiled with a10% solution of caustic soda, preferably under pressure and whileenergetically stirring; the mixture is thereupon diluted by means ofwater, so as to 8 lower the concentration of soda to about 2%, andfinally the carbon is separated from the sodium lye, e. g. by means offilter presses.

In many cases the process may be-advan tageously carried out in such amanner that after the treatment with the 10% solution of caustic sodathe mixture is settled and the supernatant sodium lye decanted,whereupon the remaining mixture is diluted as described above andfiltered. The decanted lye is then ready for reuse without needing anyconcentration.

* jThe filter cakes are washed out with water and so made suitable forreuse. 7

In the case the agent has acted upon other substances, such as fats andoils, it may be treated prior to the burning operation with suitablesolvents for the purpose of removing the-adhering oil. The. advantage ofthis is that smaller-quantity 1 ing operation.

' certain; structure proper (that of the vege J *"of sodium or calcium,etc., or by certain ac- The carbon or other purifying, filtering ordecolorizing agent may be subjected to a treatment with HCl and awashing, followed by heating. to the point of carbonization, after whichthe chemical treatment may be applied, as for example treatment withcaustic soda in the'case' e'f-carbon.

of non-porous carbon is formed and that the regeneration process can becarried out easier and quicker.

The said preliminary treatment is still of greater practical importancein the case a substantial quantity of organic matter has really beenadsorbed by the agent. v

The above described process (treating with The'formed fine carbonbeingremoved, the chemicals for the purpose of removing the regenerated agentmay also be subsequently fine carbon formed) results not only in thetreated with other chemicals, e. g. with hyremoval of substantially allthe carbon formed drochloric or nitric acid, for the object of in theburning operation, but also of many further purification. inorganicimpurities. In applying the process according to the The caustic sodause non-porous carbon may be used several again for the same purpose..The said r solution may also be employed for treating the spentdecolorizing agent prior to the burntimes sorbing agents, as e. g.kieselguhr, the burneused ing operation can be carried out attemperatures below that at which modifications may occur in thestructure, this in order to avoid agglomeration, pulverization or thelike of The factors which influence the removal. of the agent. In thecase of kieselguhr, the most the formed fine carbon out of the agentare: suitable temperature is about 300 C. or less. concentration of theapplied chemicals, tem- The organic constituents are distilled offheperature and pressure at which the treatment low said temperature,preferably with addiis performed, duration of this latter, degree tionof small quantities of air or other gases. of carbonizing, nature andmanner of the car- What I claim is: bonizing process. 1. The process ofregenerating.purifying, I The amount of chemicals to be appliedfiltering, and decolorizing agents containing should be more or'lessproportionate to the absorbed material which comprises heating amount ofcarbon formed in the burning the agent containing the absorbed materialprocess and of the amount of other impurities to the point ofcarbonization of an absorbed present therein.- The kind of chemicals tomaterial and thereafter extracting such prodbe applied will be chosen inaccordance with uct with an alkaline liquid agent capable of the natureof the agent to be treated. and removing products of carbonization ofsaid of the impurities contained therein (i. e. other material. mattersthan the carbon formed during the 2. The process of regeneratingpurifying, process). v filtering, and decolorizing agents containing Inthe practice of the process the burning absorbed material whichcomprises heating temperature should not be raised above that the agentcontaining the absorbed material to required for the regeneration ofsaid agent. the poin of carbonization of an absorbed ma- Of course theburning temperature will be terial an thereafter extracting such productdifferent for the several agents. A suitable with a caustic sodasolution. temperature for active carbon is about 400- 3. The process ofregenerating purifying, 600 C. filtering, and decolorizing agentscontaining The process is especially advantageous for absorbed materialwhich comprises heating such decolorizing carbons, which present a theagent containing the absorbed material to the point of carbonization ofan absorbed material and thereafter extracting such product with a hotcaustic soda solution.

4. The process of regenerating purifying, filtering, and decolorizingage n ts containinjg absorbed maleliiaLwhichcoiiiprises heating vecarbon can begtheagent' containing the absorbed material to such as thepoint of carbonization of an absorbed maonate terial and thereafterextracting such product with a hot caustic soda solution under pre'stive gases, such as e. g. superheated water sure. W vapor or carbondioxide, which may be added 5. The process of regenerating purifying,prior to or during the burning operation. filtering, and decolorlaingagents containing The treatment with gases may be followed absorbedmaterial which comprises prelimiby the chemical treatments referred toabove. narily removing from the agent absorbed Specifically, in theexample given with carmaterial, heating the agent to the point of bon,the burning operation may befollowed carbonization of an absorbedmaterial and by treatment wlth superheated water va or thereafterextracting such product with an I or carbon dioxide and then thechemical alkaline liquid agent capable of removing treatment applied oromitted. products of carbonization of said material.

table substances from which they are derived) arid which, incontradiction to decolorizing carbons separated from solutions, do notcontain large amounts of substances soluble in alkaline lyes:

The removal of non-acti effected by a number oi lsubstances, e. g.caustic sodium or potassium, carb d for removing the fine presentinvention for revivifying mineral ad- 6. The

process of regenerating purifying, filtering,

after extracting such product witha caustic Soda solution.

7.- The process of regenerating purifying, filtering, and decolorizlngagents contamin absorbedmaterial which comprises prelinunaril removingfrom the agent absorbed materia heating the agent to the point ofcarbonization of an absorbed material and thereafter extracting suchproduct with a hot caustic soda solutio terial, heating 8. The processof regenerating purifying, filtering, and decoloriz ng agents contamingabsorbed material which comprises reliminarily removing from the agentabsor ed mathe agent to the point of carbonization of an absorbedmaterial and thereafter extracting with a hot caustic soda solutionunder pressure.

9. The process of regenerating decolorizing carbon containing absorbedmaterial which comprises heating the carbon to the uctso terial andthereafter point of carbonization of an absorbed material and thereafterextracting with an alkaline li uid'agent capable of removingprodcarbonization' of said material.

10. The process of regenerating decolorizing carbon containing absorbed'material which comprises heating the carbon to thepoint ofcarbonization ofv the absorbed material and thereafter extracting with acaustic soda solution.

' 11. The process of regenerating decolorizing carbon containingabsorbed material which comprises heating the carbon to the point ofcarbonization of an absorbed maextracting with a hot caustic sodasolution.

12. The process of regenerating decolorizing carbon containing absorbedmaterial which comprises heating the carbon to the point ofcarbonization of an absorbed material andthereafter extracting'with ahot caustic soda solution under pressure.

13. The process of regenerating decolorabsorbed material which comprisespreliminarily removing absorbed material from the carbon, heating thecarbon to the-point of carbonization of an absorbed material andthereafter extracting with an alkaline liquid agent capable of removingproducts of carbonization of'said material.

14: The process of regenerating decolormaterial to the point at whichcarbon izing carbon .containin absorbed material which comprisespreliminarily removing absorbed material from the carbon, heating thecarbon to the point of carbonization of an absorbed material andthereafter extracting with a caustic soda solution. 15. The process ofregeneratin decolor- 1zing carbon containin absorbe material whichcomprises preliminarily removing absorbed material from the carbon,heating the carbon to the point of carbonization of an absorbed materialand thereafter extracting with a hot caustic soda solution. u 16. Theprocess of regeneratin decolorizing carbon containing absorb whichcomprises preliminarily removing absorbed material from the carbon,heating the carbon to the point of" carbonization of an absorbedmaterial and thereafter extracting with a hot caustic soda solutionunder pressure.

17. The process of regenerating purifying, filtering or decolorizingagents contaming absorbed organic material which com rises heating theagent containin the organic material to the point at whic carbon isproduced from said organic material and acting upon said so formedcarbpn'with an agent capable of removing the same from said firstmentioned agent. t

18. The process of regenerating purif absorbed organic material whichcomprises heating the agent containing the organic 1s prothereduced fromsaid organic material and carbon after extracting the said so formedfrom said agent with a liquid agent.

19. The processof regenerating decolorizing carbon containing a sorbedorganic material which comprises heating the said decolorizing carbon tothe point at which secondary carbon is formed from said organic materialand acting upon the secondary carbon with an agent capable of removingthe same from the decolorizing carbon.

20. The process of regenerating decolorizing carbon containing absorbedorganic ma-' terial which comprises heating the said decolorizing carbonto the point at which secondary carbon is formed from said absorbedorganic material and thereafter extracting the said decolorizing carboncontaining the secondary carbon with a liquid agent capable ofseparating said secondary carbon from said decolorizing carbon.

In testimony whereof I aflix mysignature.

JOHAN NlCOLAAS ADOLI' SAUIZI.-

.Yi filtering or decolorizlng agents containing material

